Proof by reductio ad absurdum is also known as proof by contradiction. It is one of the most powerful tools of reasoning at the disposal of logicians and mathematicians. Reductio proofs are used for conditionals, propositions of the form "if p then q."...

Reductio ad absurdum (Latin: "reduction to the absurd") also known as an apagogical argument, reductio ad impossibile, or proof by contradiction, is a type of logical argument where one assumes a claim for the sake of argument, derives an absurd or...

Reductio ad absurdum The import-substituting pessimism that came to the fore in the 1950s still guides policymakers in many developing countries--and in many industrial countries, for that matter. You might not think so. Economic orthodoxy has turned so firmly against this approach...

ABSTRACT-Many of the late Neoproterozoic "Ediacaran fossils" have been referred to the Cnidaria, often on the basis of vague or poorly known features. However, representatives of the living Chondrophorina (=Porpitidae, Hydrozoa), Pennatulacea (Anthozoa), and Coronatae and/or Stauromedusae (Scyphozoa) have all been identified in Ediacaran...

Politics: It's no mystery how congressional Democrats lost all momentum on Iraq: They decided to take shots at the integrity of the U.S. military. Now they stand defenseless before an outraged America."The power of the White House was too much," a dejected Senate Majority Leader...

David Tang is famous for founding the Shanghai Tang label that put Mandarin-collared shirts, cheongsam dresses and other Chinese-style fashion on boutique shelves from New York to Paris.But one of his big regrets, he says, is that the clothes aren't more popular in China.The 52-year-old...